span {
  display: block;
  width: 100px;
  height: 100px;
  margin: 160px auto;
  animation: ripple 0.6s linear infinite;
  border-radius: 50px;
 background-color: #FFF;
}

/* dalgalanma efekti */
@keyframes ripple {
  0% {
    box-shadow: 0 0 0 0 rgba(0, 128, 0, 0.1), 0 0 0 20px rgba(0, 128, 0, 0.1), 0 0 0 40px rgba(0, 128, 0, 0.1), 0 0 0 60px rgba(0, 128, 0, 0.1);
  }
  100% {
    box-shadow: 0 0 0 20px rgba(0, 128, 0, 0.1), 0 0 0 40px rgba(0, 128, 0, 0.1), 0 0 0 60px rgba(0, 128, 0, 0.1), 0 0 0 80px rgba(0, 128, 0, 0);
  }
}
